Fluid-cooled device



ril 23, 1946. B. w. JONES FLUID-COOLED DEVICE Filed April 28, 1945 Figl.

AC SUPPLY o I 0 9 mm, 24

m WT M w Inventor 7 a m w r J 0 W .m WW6 .J H W B Patented Apr. 23, 1946 FLUID-COOLED'IDEVICE Benjamin W. Jones, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application April 28, 1945, Serial No. 590,907

(CL 17731l) 7 Claims.

My invention relates to fluid-cooled devices, suchas bearings and particularly to bearings in which the cooling fluid flows through a cooling coil around the bearing and in which a signal is adapted to be operated to indicate any un-' desirable condition in the cooling system which might result in overheating of the bearing due to an inadequate supply or'a failure in the supply of the cooling liquid.

An object of my invention is to provide an improved fluid-cooled device.

Another object of my invention is to provide an improved fluid-cooled bearing with a signal system for indicating the presence of an undesirable rise in temperature of the bearing.

A further object of my invention is to provide an improved alarm signal system for indicating the presence of an undesirable rise in the temperature of a fluid cooled device.

Further objects and advantages of my invention will become apparent and my inventionwill be better understood from the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In the drawing, Fig. 1 is a side elevational view of a bearing incorporating an embodiment of my invention with a schematic representation of an alarm system to be used with such a bearing; and

Fig. 2 is a side elevational sectional view of a' thermally responsive member such as can be used in the alarm circuit provided with my improved 3 and is formed with a fluid-collecting well 5 in the underside thereof, such that a certain amount of cooling liquid will remain in this well 5 for a supply, such as a pipe 6, is connected to the coil considerable period of time, even though the cooling liquid in the supply has been cut off. A cooling fluid exhaust, including a pipe 6, is connected to the exhaust side of the cooling fluid circuit for removing the water or other co'oling fluid after it has passed through the cooling coil. It is desired that the temperature of such a bearing should not exceed a predetermined value, and this can be determined by maintaining a predetermined temperature diil'erence between the incoming and outgoing liquid. In my improved bearing construction, I provide an alarm signal system such that an operator of th equipment which is supported by the bearing I can readily determine if the predetermined temperature difference is exceeded. This alarm system includes athermally responsive member formed as a negative temperature coeflicient resistance detector 1 arranged in a location, such as the well 5 in the underside of the supply to the bcaringcooling circuit, where supply fluid is trapped, and a ther-. mally responsive member including'a negative temperature coefficient resistance detector 8 arranged in the upper side of the cooling fluid exhaust 6 to be free from trapped exhaust fluid. These thermally responsive members may be made in any suitable manner, such as that shown in Fig. 2, in which a central terminal 9 is connected to a negative temperature coeflicient resistance member III which is arranged in good electrical contact with a retaining washer I I held in the base of a tubular well member I2 adapted to be secured by threads I3 in a threaded opening such as that formed in the supply pipe 4 and the exhaust pipe 6. The outer shell or tubular well I2 forms the other terminal of the thermally responsive member and is insulated by suitable insulating supports I4, I5, I6, and H from the inner terminal 9 and its electrical connection to the control circuit. The upper end of the tubular well I2 is electrically and mechanically connected to an electrically conductive bushing member l8, a fitting I9, and a cap 20 which forms the final terminalfor the other side of the thermally responsive member. The two thermally responsive members I and 8 are connected in series circuit with exciting coils 2| and 22, respectively, of a balanced relay and to the secondary 23 of a transformer which has a primary winding 24 adapted to be connected to a suitable source of alternating current power supply. The balanced relay is providedwith two stationary contacts 25 and 25 and two contacts 21 and 28 which are adapted to engage the contacts 25 and 26, respectively, when the relay is actuated by the energization of either of the exciting coils more than the other in response to a predetermined temperature difference between the temperature of the two thermally responsive members 1 and; 8.. The energizations of these two coils will be sub-.

stantially equal and tend to maintain open the circuit between the relay contacts. Since the temperature of the outgoing cooling fluid should normally be higher than the temperature of the incoming fluid, a variable resistor 29 is arranged in circuit with the thermally responsive member 8 in the outgoing or exhaust side of the cooling circuit in order to increase the resistance in this side of the-circuit to balance any decrease in the resistance of the thermally responsive member 8 due to the increase in the temperature of the cooling fluid on this side'of the circuit. The variable resistor 29 may be adjusted to provide for the desired predetermined temperature difierence between the ingoing and outgoing cool ing liquid. With this construction, if the hearing should become overheated, an excessive temperature difference will exist between these two thermally responsive members I and 8, and the current flowing through the member 8 will be increased because of the reduced resistance in this member as compared to the resistance of the member 1. This will cause the energization of the relay coil 22 to predominate over the energization of the relay coil 2|, such that the contacts 25 and 21' will be closed and an alarm signal device, such as a visual signal lamp 30, will be energized by being connected in circuit with the secondary 23 of the transformer across the source of electrical power supply, thereby providing an indication to an attendant that the bearing is becoming overheated. If the supply of cooling fluid should for some reason he cut off while the bearing is in operation, the bearing also might become overheated, and the water which will be collected in the well 5 in the supply pipe 4 will maintain the thermally responsive member 1 at a lower temperature than the thermally responsive member 8 which will become heated by the passage of current therethrough without the benefit of the cooling effect of contact with any cooling fluid, since all of the cooling liquid will be drained from the pipe 6 under these conditions. This will result in an overheating of the thermally responsive member 8 and again produce an unbalance 'in the energization of the relay exciting coils 2| and 22, such that the coil 22 will draw down the armature of the relay and close the contacts 25 and 21, thereby energizing the relay signal device 30. If the variable resistor 29 is adjusted for a predetermined difference in temperature between the supply and exhaust cooling fluid and too large an amount of cooling fluid is used, such that the desired temperature difierence does not exist and the cooling system is, therefore, being inefliciently operated, the current through the thermally responsive member I will be greater than the current through the thermally responsive member 8,,since the circuit for the member I does not include the adiustable resistor 29, and both members I. and 8 may be near the same temperature. In this instance, the magnetic attraction of the relay coil 2i will overbalance the relay coil22 and attract the relay armature so as to close the circuit between the contacts 26 and 28, thereby energizing a circuit including an alarm signal device, such as a lamp 3|, and warn an operator of the machine of this condition, so that the supply of cooling fluid maythe variable resistor 29 may be adiusted to provide a resistance in this circuit which includes the relay coil 22, such that under normal conditions with a normal temperature or temperature difference between th supply and exhaust fluids the relay coil 2i will be energized sumciently more than the relay coil 22 so as to attract the armature of the relay and close the circuit between the contacts 26 and 28 and energize the signal lamp 3|. With this type of signal system, the lamp 3| may be made of a different color from the lamp 30 and'may provide a green signal to indicate the safe operating condition of the fluid cooling system tor the device, and the green light will remain lit for all normal temperatures of the system. If the temperature diflerence between the supply and exhaust cooling fluid exceeds a predetermined amount, the resistance of the negative temperature coefficient member 8 will be reduced sufliciently over the resistance of the member 1, such that the circuit of the system including the member 8, the variable resistance 29, and the relay coil 22 will be energized to an extent such that the relay coil 22 will attract the armature of the relay and open the circuit between the contacts 26 and 28 and close the circuit through the contacts 25 and 21 and the signal lamp device 30. This signal lamp 30 preferably is made of a different color from the signal lamp 8i and in this instance may be red, to indicate a dangerously high temperature in the cooling system of the device.

While I have illustrated and described a particular embodiment of my invention, modifications thereof will occur to those skilled in the art. I desire it to be understood, therefore, that my invention is not to lie-limited to the particular arrangement disclosed, and I intend in the appended claims to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A fluid-cooled device including a cooling fluid circuit about said device, a cooling fluid supply to said device cooling fluid circuit, a cooling fluid exhaust from said device cooling fluid circuit, a thermally responsive electrical resistance member arranged in a location insaid cooling fluid supply for trapping some of the cooling fluid, a second thermally responsive electrical resistance member arranged in said cooling fluid exhaust in a location free from trapped fluid, an electrical signal device, and means including a relay for connecting said electrical signal device to a source of electrical power supply by actuation of said relay in response-to a predetermined temperature difierence between the temperatures of said thermally responsive members.

2. A fluid-cooled bearing including a bearing member, a cooling fluid circuit about said bearing member, a cooling fluid supply to said bearing member cooling fluid circuit, a cooling fluid exhaust from said bearing member cooling fluid circuit, a thermally responsive negative temperature coeflicient electrical resistance member arranged in a well in said cooling fluid supply, a second thermally responsive negative temperature coeflicient electrical resistance member arranged in said cooling fluid exhaust in a location free from trappe'd fluid, an electrical signal-device, and means for connecting said electrical signal device to a source of electrical power supply in response to a predetermined temperature mally responsive members.

3. A fluid-cooled device including a cooling fluid circuit about said device, a cooling fluid supply to said device cooling fluid circuit, a cooling fluid exhaust irom said device cooling fluid circuit, a thermally responsive negative temperature coeficient electrical resistance member arranged in a well in said cooling fluid supply, a second thermally responsive negative temperature coefllcient electrical resistance member arranged in the upper side 01 said cooling fluid exhaust, an electrical signal device, and means including a balanced relay operable in response to a predetermined temperature diflerence between the temperatures of said thermally responsive members for connecting said electrical signal device to a source of electrical power supply.

4'. A fluid-cooled bearing including'a bearing member, a cooling fluid circuit about said bearing .member, a cooling fluid supply to said bearing member cooling fluid circuit, a. cooling fluid exhaust from said bearing member cooling fluid circuit, a thermally responsive negative temperature coefllcient electrical resistance member arranged in a well in said cooling fluid supply, a-

second thermally responsive negative temperature coefllcient electrical resistance member arranged in said cooling fluid exhaust in a location free from trapped fluid, an electrical signal device, means including a balanced relay for connecting said electrical signal device to a source of electrical power supply by actuation or said relay in response to a predetermined temperature difference between the temperatures of said thermally responsive members, and means for adjusting the resistance oi the circuit or one or said temperature responsive members.

5. A fluid cooled bearing including a bearing member, a cooling fluid circuit having a circulating coil arranged about said bearing member, a cooling fluid supply to said bearing member cooling fluid circuit, a cooling fluid exhaust from said bearing member cooling fluid circuit, a thermally responsive electrical resistance mam ber arranged in a well in the underside of said cooling fluid supply, a second thermally responsive electrical resistance member arranged in the r thermally responsive member for connecting said electrical signal device to a source of electrical power supply'by actuation of said relay when either 0! said exciting coil means'ls energized more than the other in response to a predetermined temperature diflerence between the temperature of said thermally responsive members, and means for adjusting the resistance of the circuit of one or said temperature responsive members.

6. An alarm system for a fluid-cooled device having a cooling fluid circuit, a thermally responsive electrical resistance member arranged in a location for trapping some of the cooling fluid in the supply to the cooling fluid circuit, a second thermally responsive electrical resistance member arranged in a location free from trapped fluid on the exhaust oi the cooling fluid circuit, an electrical signal device, and means for connecting said electrical signal device to a source of electrical power supply in response to a predetermined temperature difl'erence between the temperatures of said thermallyresponsive members.

'7. An alarm system for a'fluid-cooled bearing having a cooling fluid circuit, a thermally responsive negative temperature coeflicient electrical resistance member arranged in a well in the supply to the cooling fluid circuit, a second thermally responsive negative temperature coeiflcient electrlcal resistance member arranged in the upper balanced relay for connecting said electrical signal device to a source of electrical power supply by actuation of said relay in response to a predetermined temperature diflerence between the temperatures of said thermally responsive members.

' BENJAMIN W. JONES. 

